Method of producing silicon material, anode material and method of producing anode electrode of lithium-ion battery

Abstract

Provided is a method of producing a silicon material, comprising: slicing a silicon substrate with a fixed-abrasives wire to obtain a mixing slurry; and treating the mixing slurry by solid-liquid separation, so as to isolate a silicon material from the mixing slurry, which is applicable for a lithium-ion battery. With the simplified method, the production cost of silicon material is remarkably reduced. Furthermore, an anode material of a lithium-ion battery and a method of producing an anode electrode of a lithium-ion battery are provided. Since the silicon material produced by the method has high purity and fine granules, the extreme volumetric expansion of silicon under heat is largely reduced, and thus the cycle stability, electrical performance, and quality of a lithium-ion battery comprising the silicon material are improved.

What is claimed is: 
     
         1 . A method of producing a silicon material, comprising the steps of:
 providing a wire sawing tool comprising a cutting wire, a base layer disposed on the cutting wire, and multiple abrasives partially embedded into the base layer and having particle sizes ranging from 1 micrometer to 100 micrometers;   slicing a silicon substrate with the wire sawing tool to obtain a mixing slurry; and   treating the mixing slurry by solid-liquid separation, so as to isolate the silicon material from the mixing slurry.   
     
     
         2 . The method as claimed in  claim 1 , wherein the cutting wire has a diameter ranging from 80 micrometers to 500 micrometers 
     
     
         3 . The method as claimed in  claim 1 , wherein the abrasives have particle sizes ranging from 1 micrometer to 50 micrometers. 
     
     
         4 . The method as claimed in  claim 1 , wherein the step of treating the mixing slurry by solid-liquid separation comprises:
 separating the mixing slurry into a liquid mixture and a solid mixture by solid-liquid separation;   washing the solid mixture with an aqueous solution to form a washed mixture; and   treating the washed mixture by solid-liquid separation, so as to isolate the silicon material from the washed mixture.   
     
     
         5 . The method as claimed in  claim 1 , wherein the cutting wire is made of iron, copper, nickel or their combinations. 
     
     
         6 . The method as claimed in  claim 5 , wherein the step of treating the mixing slurry by solid-liquid separation comprises:
 separating the mixing slurry into a liquid mixture and a solid mixture by solid-liquid separation;   washing the solid mixture with an acidic solution to remove iron, copper, nickel or their combinations, so as to form a purified mixture; and   treating the purified mixture by solid-liquid separation, so as to isolate the silicon material from the purified mixture.   
     
     
         7 . The method as claimed in  claim 5 , wherein the step of treating the mixing slurry by solid-liquid separation comprises:
 separating the mixing slurry into a liquid mixture and a solid mixture by solid-liquid separation; and   removing iron, nickel or their combinations from the solid mixture by magnetic separation, so as to obtain the silicon material.   
     
     
         8 . The method as claimed in  claim 5 , wherein the step of treating the mixing slurry by solid-liquid separation comprises:
 removing iron, nickel or their combinations from the mixing slurry by magnetic separation to form a collected mixture; and   treating the collected mixture by solid-liquid separation, so as to isolate the silicon material from the collected mixture   
     
     
         9 . The method as claimed in  claim 1 , wherein the method further comprises drying the silicon material to obtain a powdered silicon material. 
     
     
         10 . The method as claimed in  claim 9 , wherein the silicon material is dried at a temperature ranging from 80° C. to 120° C. 
     
     
         11 . The method as claimed in  claim 1 , wherein the silicon material has particle sizes ranging from 5 nanometers to 10 micrometers. 
     
     
         12 . The method as claimed in  claim 1 , wherein the silicon material comprises silicon granules and abrasive granules, and an amount of the silicon granules is not less than 95 wt % based on a total weight of the silicon material. 
     
     
         13 . The method as claimed in  claim 1 , wherein the abrasives are made of material from the group consisting of: diamond, diamond-like carbon, silicon carbide, boron carbide, aluminum nitride, zirconium dioxide and their combinations 
     
     
         14 . The method as claimed in  claim 1 , wherein the base layer is made of resin, metal, or metal alloy. 
     
     
         15 . The method as claimed in  claim 1 , wherein the silicon substrate includes a single crystal silicon substrate, a polycrystalline silicon substrate or an amorphous silicon substrate. 
     
     
         16 . The method as claimed in  claim 1 , wherein the solid-liquid separation includes centrifuge separation, filter-pressing separation, sedimentation, membrane filtration, or decantation separation 
     
     
         17 . An anode material of a lithium-ion battery, comprising a silicon material produced by the method as claimed in  claim 1 , the silicon material having particle sizes ranging from 5 nanometers to 10 micrometers. 
     
     
         18 . The anode material as claimed in  claim 17 , wherein the silicon material comprises silicon granules and abrasive granules, and an amount of the silicon granules is not less than 95 wt % based on a total weight of the silicon material. 
     
     
         19 . The anode material as claimed in  claim 18 , wherein the silicon material has particle sizes ranging from 5 nanometers to 2 micrometers. 
     
     
         20 . A method of producing an anode electrode of a lithium-ion battery, comprising the steps of:
 preparing a silicon material produced by the method as claimed in  claim 1 , the silicon material having particle sizes ranging from 5 nanometers to 10 micrometers;   mixing the silicon material with a carbonaceous material to form a slurry; and   coating the slurry on a metal substrate and drying the slurry, so as to produce the anode electrode of the lithium-ion battery.   
     
     
         21 . The method as claimed in  claim 20 , wherein the step of preparing a silicon material comprises:
 providing a wire sawing tool comprising a cutting wire, a base layer disposed on the cutting wire, and multiple abrasives partially embedded onto the base layer and having particle sizes ranging from 1 micrometer to 50 micrometers;   slicing a silicon substrate with the wire sawing tool to obtain a mixing slurry; and   treating the mixing slurry by solid-liquid separation, so as to isolate the silicon material from the mixing slurry.